The fabrication and manufacture of goods from metals often results in the metals having a less than desirable metallurgical condition. To convert the metals to a desired condition, it is common to heat treat the metals. In heat treating, an object, or portion thereof, is heated to a suitably high temperature and subsequently cooled to ambient temperature. The temperature to which the metal is heated, the time of heating, as well as the rate of cooling, may be selected to develop the intended physical properties in the metal. For example, for normalization, steel is to be heated to a temperature above the critical range, to about 1600 degrees Fahrenheit and then cooled slowly, while tempering of steel also requires uniformly heating to a temperature below the critical range to a specified temperature, holding at that temperature for a designated time period then cooling in air or liquid.
Inductive heating is one method for producing heat in a localized area of a metallic object. In inductive heating, an alternating current electric signal is provided to a coil disposed near a selected location of the metallic object to be heated. The alternating current in the coil creates a varying magnetic flux within the metal to be heated. The magnetic flux induces current flow in the in the metal, which, in turn, heats the metal.